Meet Amblypygi

Beez Neez now Chy Whella
Big Bear and Pepe Millard
Fri 27 Jul 2012 21:45
Amblypygi Visits School
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This chap got school very excited, he was minding his own business, just having a nap on the wall. Next thing there are stories of jumping spiders leaping on cows and killing them with a single nip. I casually asked Bear to put his finger in shot for perspective, much dissuasion from onlookers. No, I said in a big voice – Our blog readers have come to expect it. My brave captain – my hero.


Amblypygi is an order of invertebrate animals belonging to the class Arachnida, in the subphylum Chelicerata of the phylum Arthropoda. They form a separate order of arachnids alongside the spiders, scorpions and others.

Amblypygids are also known as whip spiders and tailless whip scorpions (not to be confused with whip scorpions that belong to the Arachnid order Thelyphonida). The name "amblypygid" means "blunt rump", a reference to a lack of the telson ("tail") carried by related species. Despite an off-putting appearance, they are harmless to humans.

By 2003, 5 families, 17 genera and around 155 species had been discovered. They are found in tropical and subtropical regions worldwide. Some species are subterranean; many are nocturnal. During the day, they may hide under logs, bark, stones, or leaves. They prefer a humid environment.


Physical description: Amblypygids range from 4 to 10 inches in size, including leg span. Their bodies are broad and highly flattened, with a solid carapace and a segmented abdomen. They have a pair of median eyes at the front of the carapace, located just above the chelicerae in a manner somewhat similar to crustaceans, and three smaller eyes placed further back on each side, for eights eyes in total.

Amblipygids possess medium to poor eyesight, however their pedipalps, which serve as sensors for many akin arachnids, are modified and inward-adapted for grabbing and retaining prey, much like those of a praying mantis. In retrospect, the first pair of legs are also modified and act as sensory organs, while the animal uses the other six legs for walking. The sensory legs are very thin, have numerous sensory receptors, and can extend several times the length of body. Typically, the animal holds one of these legs out in front of it as it moves, and uses the other to probe the terrain to the side.

Amblypygids possess no silk glands or venomous fangs; however their chelicerae do eject a digestive acidic enzyme, unlike those of sun spiders, for example. They rarely bite if threatened, but can grab fingers with pedipalps, resulting in thorn-like puncture injury.





Behaviour: Amblypygids often move about sideways on their six walking legs, with one "whip" pointed in the direction of travel while the other probes their other sides. Prey are located with these "whips", captured with pedipalps, then masticated with chelicerae.

Courting rituals involve the male depositing stalked spermatophores, which have one or more sperm masses at the tip, onto the ground, and using his pedipalps to guide the female over them. She gathers the sperm and lays fertilized eggs into a sac carried under the abdomen. When the young hatch, they climb up onto the mother's back; any which fall off before their first moult will be eaten by the mother.

Amblypygids, particularly the species Phrynus marginemaculatus and Damon diadema, are thought to be among the few examples of arachnids which show signs of social behavior. Research conducted by entomologists at Cornell University suggests that mother amblypygids communicate with their young by caressing the offspring with her antenniform front legs, and that the offspring reciprocate both with their mother and their siblings. Further, in an experiment where two or more siblings were placed in an unfamiliar environment, such as a different cage, they would seek each other out and gather back into a group.


History: Fossilized amblypygids have been found dating back to the Carboniferous period, for example Graeophonus.



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